Devolution

Devolution is the granting of powers to a lower level of government, while preserving sovereignty to the granting level. Unlike the federal arrangements of countries such as the United States of America, devolution reserves supreme power to the granting level.

In other words, the granting level (the United Kingdom Parliament) can pass legislation which overrides legislation of the lower level (the Scottish Parliament) and it can even withdraw those powers at any time.

Former schemes of devolution in the United Kingdom:

the Government of Ireland Act, 1920 - suspended in 1972

the Scotland and Wales Acts, 1978 - both were rejected in referenda

Schemes of devolution which are implemented at present:

The Belfast Agreement, also known as the ‘Good Friday’ Agreement for Northern Ireland, 1998

the Scotland Act, 1998

the Wales Act, 1998

It is important to bear in mind that the level and amount of devolution in these three constituent countries are different, and that England has no devolved powers.